Well, they really aren't using their heads on this one... bad pun... sorry, had to do it.
Anyhoo, trails are NOT safe. My boyfriend had a horrible wreck on a trail, demolished his bike, and almost his head, if it hadn't been for his helmet.
I also know of other trail wrecks. One where someone broke a hip and another person broke their collar bone.
And I know how annoying it is... to see people riding without helmets. The other day, at the lake I ride, there was this Dad riding in the street with his son. The son, about 8 years old, was BEHIND him, on a road with cars. Neither had helmets on. WTH? How do you let your kid ride in the street, not watch them and not put a helmet on his head? GGGGRRRRR
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"